The Digital Versatile Disc (DVD) is a high-capacity multi-media data-storage medium designed to accommodate a complete movie on a single disc, content-rich multi-media or very high-quality multi-channel audio. DVDs have become quite popular, the market for DVD having grown faster than compact discs (CDs) or VHS video cassettes did during their first two years. The most popular of the DVD formats is the DVD-VIDEO format, which is a format for video content which can be played on domestic DVD players and DVD-ROM drives. The DVD-ROM format is for delivering data and multi-media content which can be played by computers equipped with DVD-ROM drives.
DVD-ROM drives are becoming quite popular and are now standard on many high-end computers. Typically, the DVD-ROM hardware is accessed by the peripheral device access functions of the operating system. The data from the DVDs is provided to DVD player software. The DVD player software allows the computer user to access the various content of the DVD. One popular use of DVDs for computer-based systems is for displays and presentations by companies to potential customers and employees.
The DVD players and discs operate in accordance with the official DVD specification, currently the DVD video specification version 1.1. The official specification was developed by a consortium of ten companies: Hitachi, JVC, Matsushita, Mitsubishi, Philips, Pioneer, Sony, Thomson, Time Warner, and Toshiba. Representatives from many other companies also contributed in various working groups. In May 1997, the DVD Consortium was replaced by the DVD Forum, which is open to all companies, and as of February 2000 had over 220 members.
A difficulty with DVD systems is that they do not allow access to information other than that stored on the DVD. Once a DVD is produced, the content of the DVD can not be updated.
It is desired to have an improved DVD system that allows access to the information not stored on the DVD itself.